This section provides background information related to the present disclosure which is not necessarily prior art.
Exhaust after-treatment systems can dose an exhaust treatment fluid into an exhaust stream to assist in removing various constituents from the exhaust. The dosing is generally done by a dosing module that is attached to an exhaust passage. The dosing module, therefore, can be indirectly exposed to temperatures that can be in excess of 400 degrees C.
To cool the dosing module as it is exposed to these temperatures, the exhaust treatment fluid can be cycled through the dosing module, or the dosing module can be provided with a cooling jacket. In the event of a shutdown of the engine producing the exhaust, no exhaust treatment fluid or cooling fluid may be cycled through the dosing module to cool it. In particular, during an emergency shutdown where all power is cut to the engine and the exhaust system, no power is available to cycle the exhaust treatment fluid or coolant through the dosing module. Without these cooling features, the dosing module can be damaged.